package demo6;

/**
 * Created by Administrator on 2017/4/5.
 */
//: Wind.java
// Inheritance & upcasting
import java.util.*;

class Instrument {
    public void play() {}
    static void tune(Instrument i) {
        // ...
        i.play();
    }
}

// Wind objects are instruments
// because they have the same interface:
class Wind extends Instrument {
    public static void main(String[] args) {
        Wind flute = new Wind();
        Instrument.tune(flute); // Upcasting
    }
} ///:~
